Automatic Control System For Connecting A Dual-Member Pipe

ABSTRACT

A system and method of making up and breaking out a dual-member drill string. The system comprises a spindle, a spindle carriage and a drive frame. The drive frame provides thrust to the spindle, while the spindle carriage provides rotation. The spindle has an outer spindle and an inner spindle, and is adapted to connect to a pipe section having an outer pipe section and an inner pipe section. Inner joints are geometrically shaped, while outer joints are threaded. When making up dual member drill string, the spindle is advanced, with the outer spindle rotating, and the inner spindle rotating in alternating directions, or “dithering.” A float sensor and a processor are used in tandem to cooperatively couple the inner spindle with the inner pipe sections and the outer spindle with the outer pipe sections.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Ser. No. 13/192,547, filed onJul. 28, 2011, which is a continuation of U.S. Pat. No. 7,987,924, filedon Dec. 7, 2009, which is a continuation of U.S. Pat. No. 7,628,226,filed on Jul. 26, 2007, which claims the benefit of provisional patentapplication Ser. No. 60/820,371, filed on Jul. 26, 2006, the entirecontents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of horizontal boringmachines, and more particularly to a makeup/breakout system fordual-member pipes.

SUMMARY OF THE INVENTION

In one embodiment the present invention is directed to a method forcoupling a carriage to a dual-pipe drill pipe section. The methodcomprises the steps of advancing the carriage having an inner spindleand an outer spindle, automatically rotating the inner spindle clockwiseand counterclockwise in an alternating fashion, and detecting a carriagefloat position. The inner spindle and the outer spindle of the carriageare connectable to a pipe section having an inner pipe section and anouter pipe section. The detected carriage float position indicates theinner spindle has not coupled with the inner pipe section.

Another embodiment of the present invention is directed to a method foradding a pipe section to a drill string. The pipe section comprises aninner pipe section and an outer pipe section. The drill string comprisesan inner pipe and an outer pipe. The method comprises the steps ofattaching a pipe section to a carriage, aligning an end of the innerpipe section with an end of the inner pipe, advancing the pipe sectionsuch that the inner pipe section is coupled to the inner pipe,monitoring a carriage float position, detecting a carriage floatposition, and coordinating rotation and thrust of the outer pipesection. The carriage is adapted to advance and rotate the pipe section,and characterized by an amount of float. The inner pipe and inner pipesection's ends are aligned such that the inner pipe section may becoupled to the inner pipe. The detected carriage float position isindicative of the inner pipe section not being coupled to the innerpipe. Thrust and rotation of the outer pipe section are coordinated suchthat the outer pipe section and the outer pipe are threaded together.

Yet another embodiment of the present invention is directed to a drillstring make-up system. The system comprises a spindle, a carriage, afloat sensor, and a processor. The spindle comprises an inner spindleand an outer spindle. The carriage is adapted to provide thrust androtation to the spindles. The inner spindle is rotatable independent ofthe rotation of the outer spindle. The float sensor is adapted todetermine the amount of float in the carriage and to transmit a floatsignal. The processor is adapted to receive the float signal and tocontrol the rotation of the inner spindle in alternating clockwise andcounterclockwise directions in response to the float signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a boring machine comprising the makeup/breakoutsystem of the present invention.

FIG. 2 is a cut-away view of a makeup/breakout system.

FIG. 3 is a side view of a spindle carriage.

FIG. 4 is a flowchart depicting a method of connecting a spindle to apipe section.

FIG. 5 is a flowchart depicting a method of coupling an inner spindle.

FIG. 6 is a flowchart depicting a method of coupling an outer spindle.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is directed to an automatic dual-pipemakeup/breakout system and a method for using the same. The system isprovided for connecting or disconnecting an existing dual-pipe drillstring to an additional dual-pipe section. Dual member pipes are usefulin conjunction with horizontal boring machines particularly in rockyconditions. With a dual member pipe, an other pipe is used for steeringthe drill string, while an independently rotatable inner member is usedto provide cutting force for a drill bit. A preferred embodiment for adual-member drill string system is disclosed in U.S. Reissue Pat. No.RE38,418, the contents of which are incorporated herein by reference. Asystem and method for the automatic connection of a one-pipe drillstring to a one-pipe spindle is given in U.S. Pat. No. 7,011,166, thecontents of which are also incorporated herein by reference.

Turning to the drawings in general and FIG. 1 in particular, there isshown in FIG. 1 a makeup/breakout system, designated by reference number10 in accordance with the present invention for use with a horizontalboring machine 11. The makeup/breakout system 10 is generally secured toa drill frame 12 of a boring machine. The makeup/breakout system 10 isoperated and monitored with controls located at an operator's console13. The operator's console 13 contains a control panel having a display,joystick, and other machine function control mechanisms, such asswitches and buttons. From the control panel, each of the underlyingfunctions of the boring machine 11 can be controlled. The display on thecontrol panel may include a digital screen and a plurality of signalingdevices, such as gauges, lights, and audible devices, to communicate thestatus of the operations to the operator. A processor 14 is adapted torespond to signals from various sensors of the system 10 and adjustfunctions of the system in response to the signals. The system 10further comprises a pipe handling system 15 supported on the drill frame12 for placement of sections of pipe for the operations described below.

Turning now to FIG. 2, the system 10 generally comprises a drive frame16, a spindle carriage 17 supported on the drive frame and a spindle 18.The system 10 comprises a front clamp wrench 19, shown in FIG. 1, andpipe loader grippers (not shown). The front clamp wrench 19 is locatedat a front end of the drill frame 12 and adapted to prevent rotation ortranslation of a dual member drill string 22. The pipe loader grippersare located on the pipe handling system 15 and adapted to preventrotation or translation of a pipe section 24.

With reference again to FIG. 2, the drive frame 16 is adapted to providepower to the spindle carriage 17. The spindle carriage 17 is supportedon the drive frame 16 and adapted to support and provide rotation andthrust to the spindle 18. As used herein, thrust is intended to mean theadvancement or retraction of the carriage 17. Preferably, the spindlecarriage 17 is connected to the drive frame 16 by a spring-centeringdevice 26. The spring-centering device 26 biases the spindle carriage 17to a default position relative to the drive frame 16.

As depicted in FIG. 2, the system 10 is connected to the dual-memberdrill string 22 by way of the spindle 18. The dual-member drill string22 is made up of a plurality of pipe sections 24. Each pipe section 24comprises an inner pipe section 30 and an outer pipe section 32.Preferably, each outer pipe section 32 has threaded male and female endsfor threaded connecting to other pipe sections. Preferably, each innerpipe section 30 has geometrically formed male and female ends for torquetransmitting slip fit connection to other inner pipe sections. As thoseskilled in the art will appreciate, alternatives to the threadedconnections of the outer pipe sections 32 and the geometricalconnections of the inner pipe sections 30 are contemplated.

The spindle 18 comprises an inner spindle 34 and an outer spindle 36.The outer spindle 36 preferably comprises a threaded spindle pipe joint38. The inner spindle 34 preferably comprises a geometrical spindle pipejoint 40. The threaded spindle pipe joint 38 is adapted for connectionto a threaded pipe joint 42 on a first end of the outer pipe section 32.The geometrical spindle pipe joint 40 is adapted for connection to ageometrical pipe joint 44 on a first end of an inner pipe section 30.Preferably, the geometrical pipe joints 40, 44 comprise hex joints. Asused herein, a pipe joint can be either of the male or female ends of apipe section 24.

The processor 14 is adapted to receive signals from a float sensor 60and a rotation pressure sensor 61. The processor 14 receives andinterprets the signals, and automatically adjusts thrust and rotation ofthe spindle 18 as will be discussed further below.

The float sensor 60 is used to measure the relative amount of floatbetween the spindle carriage 17 and the drive frame 16. Preferably, thefloat sensor 60 is an electromagnetic absolute position sensor, thoughother devices could also be used, such as linear variable displacementtransducers, photoelectric devices, resistive potentiometers, andultrasonic sensors. In the embodiment illustrated in FIG. 3, the floatsensor 60 comprises a sensor rod 62, a magnet 64, and associatedelectronics 66. The sensor rod 62 is secured to the drive frame 16. Themagnet 64 is coupled to the spindle carriage 17. The magnet 64 ispositioned to move along the sensor rod 62 as the carriage 17 floatsrelative to the drive frame 16. The associated electronics 66 areadapted to determine the position of the magnet 64 along a length of thesensor rod 62 and transmit a float signal indicative of the amount ofrelative float. Position sensors such as this are common in the art andmany alternative sensors may be contemplated for use with the presentinvention.

With reference generally to FIG. 4, shown therein is a preferredprocedure for connecting the spindle 18 to a pipe section 24. Theroutine begins at 300 and is equally applicable to the system 10 in adrilling or a backreaming mode. At 302, a check is made to see if thespindle 18 is in a rear of the drill frame 12, the front clamp wrench 19is closed, and the drilling machine is operating in the drilling mode.If the machine is operating in the drilling mode, acting in parallel,the processor 14 will have begun a routine to activate the pipe handlingassembly 20 to load a pipe section 24. At 304, a check is made to see ifthe pipe section 24 is in position for adding. If so, connection of thespindle 18 to a pipe section 24 may begin. If the answer was no at 302,the routine checks at 306 to see if the spindle 18 is at a front of thedrill frame 12, the front clamp wrench 19 is closed, and if the drillingmachine is in the backreaming mode. If so, connection of the spindle 16to the drill string 22 may begin.

At 308, the rotation and thrust of the spindle 18 is begun as aconnection routine is started. The connection routine is described belowin FIG. 6. It will be appreciated that thrust of the carriage 17 androtation of the spindle 18 should be coordinated by the processor 14. Ifthe carriage 17 is applying too much thrust or too little thrust, thecarriage 17 will displace from the default position relative to thedrive frame 16. The float sensor 60 signals this displacement, and theprocessor 14 automatically adjusts the thrust and/or rotation so thefloat sensor 60 will move back to the default position. If the floatsensor 60 reaches a limit, or is significantly displaced while rotationis not occurring (thus keeping the spindle 18 from coupling with a pipesection 24), a limit signal is sent to the processor 14 and thrustand/or rotation are automatically stopped.

In the drilling mode, the pipe handling system 15 will place a pipesection 24 comprising an inner pipe section 30 and an outer pipe section32 into a position proximate the spindle 18. The pipe holders of thepipe handling system 15 grip and hold the pipe section 24 in place. Oneof skill in the art will appreciate the pipe handling system 15 canposition the pipe section 24 and prevent some rotation of the pipesection as the spindle 18 is connected.

While the carriage 17 is advanced and the outer spindle 36 rotates, thedithering of the inner spindle 34 is begun at 310. The dithering processis more fully described below in regards to FIG. 5. “Dithering”comprises the alternate rotating of the inner spindle 34 in a clockwiseand counterclockwise fashion.

Dithering is needed because the geometrical spindle pipe joint 40 of theinner spindle 34 may contact the geometrical pipe joint 44 of the innerpipe section 30 if the joints are not geometrically aligned to permitcoupling of the joints. This contact displaces the spindle carriage 17from the drive frame 16 as the carriage advances, causing the floatsensor 60 to become displaced from the default position. When anorientation of the geometrical pipe joint 44 of the inner pipe section30 matches an orientation of the geometrical pipe joint 40 of the innerspindle 34, the inner spindle and the inner pipe section will couple.

When dithering, the clockwise and counterclockwise rotation amount ofthe inner spindle is kept approximately the same using a sensor whichprovides inner spindle 34 rotation travel information. Preferably, theinner spindle 34 is rotated through a 180 degree arc to achievecoupling. After each rotation, the travel of the spindle is read andcompared to a target travel. If the actual inner spindle 34 travel isnot equal to the desired travel, a correction can be made to the innerspindle on a next movement. If the float sensor 60 detects that thefloat position reaches a limit at 312, a speed or an orientation of theinner spindle 34 may be alternatively adjusted, an inner spindlerotation direction changed, and dither restarted at 314. Preferably, theangle of inner spindle 34 rotations may be adjusted to geometricallyalign the joints. Alternatively, an operator may override the automatedprocess and match the orientation of the inner spindle 34 to theorientation of the inner pipe section 30. When the inner spindle 34begins to couple with the inner pipe section 30, the spring centeringdevice 26 will force the spindle carriage 17 to a default floatposition.

In the preferred embodiment, the outer spindle 36 does not contact theouter pipe section 32 until the inner spindle 34 couples with the innerpipe section 30. When the inner spindle 34 aligns with the inner pipesection 30, the spring centering device 26 pushes the spindle carriage17 back to a default float position, which further couples the innerspindle to the inner pipe section. Preferably, the threaded joint 42 ofthe outer pipe section 32 will begin to couple with the threaded pipejoint 38 of the outer spindle 36 as the inner spindle 34 is coupled. Oneskilled in the art will appreciate that improper coupling of a threadedjoint on a pipe section may cause the locking or stripping of thethreads.

In order to avoid stress on the threads, rotation and thrust of thespindle 18 is coordinated by the float sensor 60 and the processor 14 toensure proper coupling. If the spindle 18 is rotating it is assumed bythe processor 14 that the spindle is being threaded to or from the pipesection 24. The processor 14 synchronizes the thrust speed with therotation to keep the float in its default position. If the drive frame16 gets too far ahead of the spindle 18 mechanism, the float positionwill be off center at 316, and thrust is stopped at 318 until rotationcatches up and the spindle carriage 17 moves back toward the centerposition. Likewise, if the spindle carriage 17 gets too far ahead of thedrive frame 16 at 316, rotation will be slowed or stopped at 318 untilthrust catches up with the drive frame and re-centers float.

The system further comprises the rotation pressure sensor 61 as anadditional way of checking whether connections are properly made up.When the outer spindle 36 is coupling with the outer pipe section 32,the sensor will detect substantially constant rotation pressure. Whenthe coupling is complete, the rotation of the outer spindle 36continues, and the rotation pressure may spike. The processor 14 detectsthe rise in the rotation pressure sensor signal and determines that thecoupling is complete. The processor 14 then may stop the rotation of thespindle carriage 17. Preferably, the pipe joints are adapted such thatwhen threads on the outer pipe section 32 are fully made up the slidinggeometrical pipe joints 40, 44 are fully seated.

If in drilling mode, the rotation pressure sensor will not sensecompleted connection until the pipe section 24 is connected to the drillstring 22. Rotation and thrust of the spindle 16 are continued as thepipe section 24 is advanced towards the drill string 22. To connect thepipe section 24 to the drill string 22, the front clamp wrench 19 isclosed about the drill string. The first pipe section 24, coupled to thespindle 18, is then advanced, and the inner pipe section 30 is dithered.Preferably, the inner pipe section 30 must be coupled to the inner pipesection of the drill string 22 before the outer pipe section 32 contactsthe outer pipe section of the drill string. The float sensor 60 and therotation pressure sensor detect at 320 when coupling of the pipe section24 and the drill string 22 is complete and rotation and thrust arestopped at 322.

Upon coupling the pipe section 24 to the drill string 22, the frontclamp wrench 19 opens and the pipe grippers of the pipe handling system15 are retracted to allow drilling operations to resume at 324. Rotationand thrust of the spindle 18 cause the drill string 22 to advance, untilsuch time as the spindle carriage 17 reaches a front end of the drillframe 12 and the process of adding another pipe section 24 is repeated.

The flow chart of FIG. 5 depicts an example of logic used by theprocessor 14 during the dithering of the inner spindle 34. The routinewaits at 402 for a signal that the spindle 18 is in a dither zone 404.The dither zone is defined as the position of the spindle carriage 17either at the rear of the drill frame 12 when the spindle 18 is to beconnected to a pipe section 24 or at the front of the drill frame whenthe spindle is to be connected to the drill string. If the spindle 18 isin the dither zone at 404, the routine asks if the wrench is closed at406. At 408, the routine asks if outer spindle 36 rotation is clockwise.If not, a check is made at 410 to see if thrust is forward. If thrust isforward at 410, or if outer spindle 36 rotation is clockwise at 408,then the inner spindle 34 is rotated at 416.

The routine waits for a given time to allow the rotation of the innerspindle 34 to expire at 418. When the time is expired at 418, theprocessor 14 checks the dither angle at 420. An incorrect ditheradjustment will require the processor 14 to calculate the ditheradjustment at 422 and adjust the dither speed at 424. Finally, thedirection of rotation of the inner spindle 34 is reversed at 426. Themakeup/breakout process can proceed at 428.

A logic sequence for the processor 14 to follow for coordinating thrustand rotation of a threaded outer spindle 36 and outer pipe section 32during pipe makeup/breakout, is shown in FIG. 6. The processor 14 beginsat 502. The processor 14 checks that the spindle 18 is in a float zoneat 504 and that the front clamp wrench 19 is closed at 506. With theseconditions met, a request for rotation is read at 508. If a request forrotation is present at 510, the rotation speed of the outer spindle 36is limited at 512, an output for thrust based on rotation is calculatedat 514 by the processor 14, and a float position is read at 516. If arequest for rotation is not present at 510, a request for thrust is readat 518. If a request for thrust is present at 520, thrust speed islimited at 522 and the float position is read at 516. If float is notcentered at 524, and float is not at a limit at 526, thrust adjustmentis calculated at 528, thrust speed is adjusted at 530, and themakeup/breakout process may continue at 532. If the float is at a limitat 526, thrust or rotation is stopped as needed at 534, and themakeup/breakout process continues at 532. If no thrust request ispresent at 520, thrust and rotation of the outer spindle 36, if any, isstopped at 536 and the makeup/breakout process may continue at 532.

Various modifications can be made in the design and operation of thepresent invention without departing from its spirit. For example, theinner pipe may be threaded or connect in a snap-together or locktogether manner. Other configurations of the outer pipe are alsoapplicable. Measurements other than float, such as contact, proximity,pressure, force or torque can be utilized for controlled coordination ofthe dual-pipe drill string. Thus, while the principal preferredconstruction and modes of operation of the invention have been explainedin what is now considered to represent its best embodiments, it shouldbe understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically illustratedand described.

1. A drill string make-up system comprising: a drive frame; a spindlecomprising an inner spindle and an outer spindle connectable to a pipesection having an inner pipe section and an outer pipe section; a meansfor providing thrust and rotation to both the inner spindle and outerspindle, wherein the inner spindle is rotatable and thrustableindependent of the outer spindle; and a float sensor to indicate a floatposition of the inner spindle; and a processor to generate a request forthrust or rotation of the inner spindle in response to signals from thefloat sensor.
 2. The system of claim 1 wherein the inner pipe sectioncomprises a threaded connection.
 3. The system of claim 1 wherein theinner pipe section comprises a geometrically formed torque-transmittingslip fit connection.
 4. The system of claim 3 wherein the geometricallyformed slip fit connection comprises a hexagonal joint.
 5. The system ofclaim 1 wherein the processor automatically controls rotation of theinner spindle over less than 360 degrees in alternating clockwise andcounterclockwise directions in response to the float signal.
 6. Ahorizontal boring machine comprising a makeup/breakout system, themakeup/breakout system comprising: a drive frame; a spindle comprisingan inner spindle and an outer spindle connectable to a pipe sectionhaving an inner pipe section and an outer pipe section; a carriagesupported on the drive frame to provide thrust and rotation to both theinner spindle and the outer spindle, wherein the inner spindle isrotatable and thrustable independent of rotation and thrust of the outerspindle; a float sensor to determine the amount of float between thecarriage and the drive frame and to transmit a float signal indicatingthe inner spindle has not coupled with the inner pipe section; and aprocessor to receive the float signal and to adjust the inner spindleand outer spindle in response to the float signal.
 7. The system ofclaim 6 wherein the float sensor comprises centering springs.
 8. Thesystem of claim 6 wherein the float sensor comprises: a sensor rodsecured to the drive frame; a magnet secured to the carriage andpositioned to move along the sensor rod as the carriage floats relativeto the drive frame; and a circuit to determine the position of themagnet along a length of the sensor rod and transmit the float signal tothe processor.
 9. An HDD system comprising: a drilling machine; acarriage supported on the drilling machine, the carriage comprising aninner spindle and an outer spindle; and a drill string comprising aninner member operatively connectable to the inner spindle and an outermember operatively connectible to the outer spindle; and a processor tocommand the carriage to connect the inner member of the drill string toan inner member of a pipe section; a float sensor supported by thedrilling machine to detect a carriage float position indicative ofwhether the inner member of the pipe section connected to the innerspindle is coupled to the inner member of the drill string and totransmit a float signal to the processor.
 10. The system of claim 9further comprising a downhole tool operatively connected to an end ofthe drill string.
 11. The system of claim 10 wherein the downhole toolcomprises a directional drilling tool.
 12. The system of claim 10wherein the downhole tool comprises a bent sub used to deflect thedrill, bit from a linear path.
 13. The system of claim 9 wherein thefloat sensor comprises: a sensor rod secured to the drive frame; amagnet secured to the carriage and positioned to move along the sensorrod as the carriage floats relative to the drive frame; and a circuit todetermine the position of the magnet along a length of the sensor rodand transmit the float signal to the processor.
 14. The system of claim9 wherein the float sensor comprises an electromagnetic position sensor.15. The system of claim 9 further comprising a pipe handling systemadapted to load the pipe section into the carriage.
 16. The system ofclaim 9 wherein the processor further commands the carriage to connectthe outer member of the drill string to an outer member of a pipesection.
 17. The system of claim 9 wherein the processor furthercommands the carriage to connect the inner member of a pipe section tothe inner spindle.